'No doubt' prince tied to Khashoggi murder: US senator

"Just from what we know about Saudi Arabia, what we know about the crown prince and what we know about this murder leaves you with no doubt that the crown prince, at a minimum, knew about it and condoned it, and perhaps at worst was actually involved in directing it," Rubio told CNN.

The senator said he knows bin Salman was involved in the murder because he has "absolute control" of the country.

"Saudi Arabia is not some decentralized government that operates with all sorts of people acting independently," he added. "Everything there is very tightly controlled."

The comments come one day after CIA Director Gina Haspel briefed a select group of lawmakers on the agency's intelligence regarding Khashoggi's murder on Oct. 2 in the Saudi consulate in Istanbul.

Rubio was not among the group, but said as a member of the Senate intelligence committee he had prior knowledge of it.

"Everything they knew, whatever they learned in that meeting, we've known," he said.

Asked why U.S. President Donald Trump and his senior officials have obviated on placing responsibility directly with bin Salman, Rubio said in his view "they are trying to preserve from a realistic perspective the importance of the Saudi-US alliance, which I agree with.

"It is a critical one. But all alliances have buffers, all alliances have limits," he said. "And the crown prince will continue to test the limits of this alliance until those limits are clearly set."

Saudi Arabia had offered changing explanations for Khashoggi's murder, initially saying he left the consulate alive before admitting weeks later the journalist was killed there while blaming his death on a group of rogue Saudi operatives.